In relevant art, the dedicated cellular wireless communication network has already been able to provide service for aircrafts, such that people on the airplane can obtain popularized and economic mobile communication services which include voice service and packet data service. FIG. 1 is a schematic diagram of a ground base station covering an aircraft in relevant art. As shown in FIG. 1, the covering is basically implemented as follows: a certain number of base station networks with the suitable layout are built on the ground, the antennae inclines upwardly to cover a civilian aviation airspace, and the aircrafts are installed with mobile communication terminals and antennae thereof to communicate with the ground base stations.
Currently, the mobile communication terminal antennae installed on the aircrafts generally use wide aperture omnidirectional antennae which has relatively small gain and cannot effectively amplify the signals of the main serving base stations and cannot restrain the interference signals of adjacent base stations. Although according to normative wireless plan design, using omnidirectional antennae can meet basic communication quality requirements, there are still disadvantages in such aspects as the capacity and coverage of the system, especially the limitation on the applications of high speed packet data service is relatively apparent. For example, one of three mainstream technologies of 3rd Generation (abbreviated as 3G) communication is code division multiple access (abbreviated as CDMA) 2000 1xEV-DO communication system, in which relatively high data rate proposes relatively high requirements to signal to noise ratio of the forward links, for example, the 2.4 Mbps download rate of the physical layer requires the signal to noise ratio at least greater than 11 dB, and the rate of 921 kbps also requires the signal to noise ratio at least greater than 2 dB. However, in the wide soft handoff area, the signal power of present base station is approximate to or even smaller than the signal total power of an adjacent base station, and the forward signal to noise ratio is often in the range of 0 dB to −3 dB, which can only achieve the rate below several hundreds kbps. Therefore, this antenna type has relatively apparent limitation on the area proportion of the airspace in which high rate can be achieved, and in the soft handoff area with very large area proportion, only the medium and low data rate can achieved.
As aviation users belong to business high-end users, only using omnidirectional antennae with ordinary performance as terminal antennae is a kind of resources waste for the expensive ground network and aviation equipment. In order to remedy the defects of currently aircraft cellular communication technology, there needs a technical solution urgently.